Lifting slip-joint



April 19, 1949. l. w. HENDERSON ET AL 2,457,826

LIFTING SLIP-JOINT Filed Feb. 5, 1947 INVENTOR.

n BY Patented Apr. 19, 12949 LIFTING SLIP-JOINT Ira W. Henderson,Detroit, Mich., and Hans T. Nilsen, Mathews, Va., assignors to RaymondConcrete Pile Company, New York, N. Y., a corporation of New JerseyApplication February 5, 1947, Serial No. I*726,658

(Cl. (il-78) 2 Claims.

An object of this invention is to disclose ways and means foreconomically sinking into the ground concrete piles of unusual lengthunder unusually diflicult conditions. This invention is an improvementon that disclosed in Upson U. S. Patent No. 1,836,140.

In that patent the shell is made in sections, each larger in diameterthan the one below it, and each adapted to surround one of thecylindrical steps of a drive core. Although the patent shows shellsections of diiierent diameters the present invention applies just aswell if the sections are of uniform diameters.

To save cost it is desirable to form the shell of as thin material aspossible, which means that the shell must be pulled into the groundunder tension instead of being pushed or driven down under compression.In order to reduce wear and tear of the soil on the shell sections, arigid ring of slightly greater diameter than the shell section, isprovided to plow a path for each section. Since the shell must havesuflicient rigidity to withstand the compression of the surroundingearth after the core is removed and before the concrete is poured, themetal of the shell is preferably corrugated, thereby providing thenecessary resistance against crushing.

Shoulders on the drive core are utilized to push down the plow rings andthe plow rings serve to pull down the shell sections.

Under certain diicult conditions, such as driving through clay intohardpan, it has been found that some of the bottom shell joints pullapart due to heaving of the ground, allowing water and mud to enter theshell. To overcome that diiculty the present inventors conceived theidea of inserting, at an appropriate point in the shell, a combinationlifting slip-joint strong enough, and rigid enough, to hold the shellstogether and in alignment during shelling-up and other handlingoperations, but weak enough to slip longitudinally if the upper part ofthe shell heaves.

There are two plow rings in the joint, each having upwardly anddownwardly extending annular fins. The upper n of the inner ring isattached to the bottom of a shell section, and has its lower finattached to a downwardly extending corrugated Screw collar which isthreaded into the upper end of the next lower shell section. The collarhas only two or three corrugations, and the gauge of the material islighter than that of the shell sections.

The upper end of the lower shell section has attached to it the otherplow ring. To the upper iin of that ring is attached a plain cylindricalsleeve extending upwardly around the lower end of the shell sectionabove it with packing between the sleeve and the shell. The corrugatedscrew collar serves to hold the shell together during all handling andshelling-up operations, and then, should the ground heave, this collarslips over the corrugations oi the shell section, and the upper plowring leaves the lower ring, the lower end of the whole shell beinganchored in the hardpan. But no harm is done because the entry of mudand water is prevented by a tubular sleeve and packing. inserted betweenthe sleeve and the shell.

Further and other objects and advantages will be apparent from thespecification and claims, and from the accompanying drawings whichillustrate what is now considered the preferred embodiment of theinvention.

In the drawings:

Fig. 1 shows a driven shell incorporating the invention;

Fig. 2 is an enlarged sectional view showing the invention in detail.

In Fig. 1 the shell has been driven into ground I0. The shell comprisescorrugated sections I2, I4, IE, I8 and 2D, each larger in diameter thanthe one below it. Sections I4 and I6 are joined together by thestructure of the invention, which will be described in detail. The othersections are provided at their lower ends with plow rings 22, 24, 26 and28, each slightly larger in diameter than the shell section to which itis attached. A plate 3U closes the bottom of the shell.

Referring to Fig. 2, 32 is a tubular drive core having a shoulder 34resting on the upper side of plow ring 36, which has an upper fin 38attached to the lower end of shell I6, and a lower n 40 to which isattached the top of a short corrugated collar 42 of comparatively lightgauge metal, and screwed into the top of shell I4.

Underneath ring 36 is a somewhat similar ring 44 having a downwardlyextending iin 46 connected to the top of shell section I4, and anupwardly extending fin 48 attached to the bottom of a tubular sleeve 50which extends upwardly outside of, and closely adjacent to, the lowerend of shell section I6.

The space between -shell I6 and sleeve 50 is calked with packing 52,thus preventing passage of water or mud. Should the joint be subjectedto suicient stress to raise ring 36 from ring 44, the corrugations ofcollar 42 will deform sufciently to slip relatively to shell I4, but nowater or mud will enter the shell past sleeve 50.

It is to be understood that the invention is not limited to the specicembodiment herein illustrated and described but may be used in otherways without departure from its spirit as defined by the followingclaims.

What is claimed is:

l. Means for joining upper and lower adjacent corrugated sections of ashell for a concrete pile, comprising in combination, a plow ring at thebottom of said upper section, a corrugated collar extending downwardlyfrom said ring and screwed into the top of said lower section, a ring atthe top of said lower section and in contact with the underside of saidfirst-mentioned ring, and a tubular sleeve extending upwardly from thetop of said lower section and surrounding the bottom of said uppersection.

2. Means for joining upper and lower adjacent corrugated sections of ashell for a concrete pile, comprising in combination, a plow ring at thebottom of said upper section, a corrugated collar REFERENCES CITED Thefollowing references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,836,140 Upson Dec. l5, 1931

